PORTLAND – The Navy’s decision to build a third DDG-1000 destroyer was driven in part by political pressure from New England but also reflects a need to maintain the nation’s shipbuilding infrastructure, a defense analyst said Tuesday.

Loren Thompson of the Lexington Institute said he was not surprised that the Navy had backed away from last month’s decision to halt the Zumwalt destroyer program at two ships and continue to build DDG-51, or Arleigh Burke, destroyers.

In addition to seeking a third Zumwalt, which would be built at Bath Iron Works in Maine, the Navy now intends to reprogram funds to buy spare DDG-51 parts and could use the money to restart the DDG-51 line, Sen. Susan Collins, R-Maine, said Monday.

Thompson said in a telephone interview that the decision was good news for Bath Iron Works and Northrop Grumman’s Ingalls shipyard in Pascagoula, Miss.

“It was pretty obvious that there was going to be a gap in the workload and the cash flow for places like the Bath Iron Works if the Navy tried to shift back to the Arleigh Burke destroyer quickly,” Thompson said.

He said the Navy soon realized the potential damage of a poorly planned transition and was surprised at the outcry from the New England congressional delegation.

“Almost everybody in New England was up in arms about this surprise decision to stop building the Zumwalt class,” he said.

Senators from Massachusetts, Maine and Rhode Island had urged Defense Secretary Robert Gates to reconsider the Navy’s plan. Led by Sen. Edward Kennedy, D-Mass., lawmakers had threatened to block future shipbuilding funds unless military officials could provide a better rationale for their decision.

Collins, who sits on the Senate Armed Services Committee, said the Navy’s turnabout represents the best of both worlds for the Bath yard, a unit of General Dynamics. She said it means that construction of a third Zumwalt is likely to go forward while the potential is still there to build more Arleigh Burkes.

Rep. Tom Allen, a Maine Democrat who is challenging Collins in this year’s Senate race, agreed that the Navy’s response was due in part to congressional pressure and said the workload at Bath Iron Works would likely remain stable without the third Zumwalt as long as at least one additional Arleigh Burke is included in the budget for 2009.

Allen said in a telephone interview that the top Navy brass maintains that the DDG-51 is better equipped to deal with the emerging threat posed by incoming missiles, a claim that Thompson said is subject to debate.

A Senate panel has authorized $2.6 billion for the third Zumwalt in its defense spending bill, but the House version does not include the funding. The DDG-51 is roughly half the price of the DDG-1000, which features stealth technology and an unconventional wave-piercing hull.

“The Navy is getting pushback on the argument that the Arleigh Burke is better on missile defense than the DDG-1000 would be,” he said. “There’s a certain kind of sleight of hand involved in claiming that Cold War destroyers are better at that mission than more modern radars and missiles would be.”

Allen, however, made it plain that he has no objection to a third Zumwalt.

“Hey, if we get a third DDG-1000 and it’s going to Bath, that works for me. It’s good for the workers, it’s good for the yard. But I want to be sure that the ongoing program is one that’s going to last for a while, and that’s almost certainly going to be the DDG-51 program.”

AP-ES-08-19-08 1301EDT